Drill and clean-out for blind holes

ABSTRACT

A clean-out drill for filling and cleaning out the residue of drilling from blind holes is provided by the combination of a drill shank having helical relief flutes and with a reduceddiameter cutting terminal section of selected diameter and length providing a shoulder spaced from the cutting tip, and with a simple washer fitted over the reduced-section drill shank and welded to the abutment lands between the relief flutes on the drill shank. The circular hole of the washer cooperates with the relief flutes to provide discharge passageways through which the residue of drilling is moved from one side to the other side of the washer for effecting discharge by centrifugal force laterally of the blind hole.

QR 3552503. SR;

7 United States Patent 2,886,291 5/1959 Frisby 2,964,115 12/1960Clatfelter ABSTRACT: A clean-out drill for filling and cleaning out theresidue of drilling from blind holes is provided by the combination of adrill shank having helical relief flutes and with a reduced-diametercutting terminal section of selected diameter and length providing ashoulder spaced from the cutting tip, and with a simple washer fittedover the reduced-section drill shank and welded to the abutment landsbetween the relief flutes on the drill shank. The circular hole of thewasher cooperates with the relief flutes to provide dischargepassageways through which the residue of drilling is moved from one sideto the other side of the washer for effecting discharge by centrifugalforce laterally of the blind hole.

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INVENIOR. CHARLES S. LES/1R .ATTORNE Y DRILL AND CLEAN-OUT FOR BLINDHOLES BACKGROUND OF THE INVENTION This invention relates to a clean-outdrill for drilling and cleaning out the residue from blind holes.

In drilling blind holes in material such as concrete, it is frequentlydesirable to limit the depth of the blind hole and to insure that thedust-like residue of drilling is substantially completely evacuated fromthe hole. Heretofore it has been an additional expense to clean outdrilling residue from blind holes in concrete after the drilling hasbeen effected.

Accordingly, it is an object of this invention to provide an improvedtool which not only provides for drilling blind holes of a proper depthin concrete and the like but which also effects cleaning out of thedrilling residue from the blind hole.

Another object of this invention is to provide a tool that ischaracterized by simplicity and inexpensiveness of construction and byefficiency of operation.

Further objects and advantages of this invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize this invention will be pointed out with particularity inthe claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view showing in sideelevation the improved drill of this invention and illustrating in crosssection the use of the drill in concrete;

FIG. 2 is a fragmentary view of the improved drill, enlarged to moreclearly illustrate the details of construction; and

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,illustrates generally a clean-out drill for use in drilling blind holesof a selected diameter and depth, such as at H, in a concrete body C.The drill 10 has an elongated cylindrical shank, generally indicated at12, of a length greater than the selected depth of hole H. The drillingend of drill It) is formed with a plurality of helical, hole-sizing,edges 14 that bound a pair of helical, relief flutes 16. Between theends of drill shank 12 there is provided an abutment shoulder 18 thatfaces in a direction toward the drills cutting end. The shank 12 isnormally selected of a diameter greater than the selected diameter ofthe blind hole, so that in order to provide for sizing the hole II tothe desired size, the tip length of shank 12 below shoulder 18 isselected to correspond with the depth of hole H and the diameter isreduced relative to the remainder of cylindrical shank 12. Thereduced-diameter portion of the shank is indicated at 12a, the helicalhole-sizing edges of shank 12a indicated at 14a, and the helical reliefflutes of reduced dimension are indicated at 16a.

The tip end of the drill is provided with cutting edges 20. The spacingof the cutter edges 20 from the plane of shoulder 18 corresponds to thedepth of hole H by being slightly greater than the depth of the hole soas to provide for an abutment mounted on the drill 10. In the specificform shown, the abutment is in the form ofa simple annular washer 22with a central hole 24, slip-fitted over the reduced shank portion 12a,the size of the central hole 24 being such as to be just slightlygreater than the diameter of reduced shank portion 120 and less than thediameter of shoulder 18. This permits one side of the flat washer 22 toabut against the shoulder 18, with portions of the central hole 24spaced from the concavity of each relief flute 16a so as to provide, bycooperation between the washer and the helical flutes, a plurality ofcontinuous, unobstructed, passageways which communicate spaces onopposite sides of the washer through the plane of the washer 22. Thewasher 22 is secured to the drill shanklZ by any appropriate means, suchas by the spaced welds 26 located only at points of abutment between thelands of shank I2 and the upper, or back, surface of washer 22.

From the foregoing and from reference to FIG. 1, the usage and operationof the device willbe readily understood. When using the drill 10 todrill blind holes H, as illustrated in FIG. I, the front side of washer22 serves as an abutment which en gages the surface of body C to limitthe depth of penetration of the reduced shank portion 12a. As the drillIt) continues to be rapidly rotated after the washer 22 has engaged thesurface of body C, a centrifugal force is imparted to the residue ofdrilling and causes such residue to move longitudinally away from cutteredges 20 helically rearwardly along the flute portions 16a and throughthe openings partially bounded by the central hole 24 of washer 22 to apoint above washer 22, where the rapid rotation of the shank 12 operatesto discharge the drilling residue by centrifugal force outwardly of there gion of hole H.

While the abutment for limiting depth of penetration has been shown inthe form of a washer, it will he understood that the shoulder 18 itselfcould serve the same purpose, and other structures could be used for thesame purpose. Thus, if the washer is considered as one or a plurality ofarms extending radially outwardly of the shank and being joined togetherin a plane, then it can be seen that the same advantages could beobtained by other forms of the invention. Included in my concept is theuse of an elongated pinlike member secured in a bore provided in theshank of the drill transversely to the longitudinal axis of the drill.

It will be obvious to those skilled in the art that various otherchanges and modifications may be made in the invention without departingtherefrom and, therefore, it is intended in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

Iclaim:

l. A clean-out drill for drilling in concrete, and cleaning out the dustand residue of drilling concrete from, blind holes of a selecteddiameter and depth comprising, in combination: an elongated cylindricaldrill shank of a length greater than the selected depth of the blindhole and terminating at a cutting tip in cutter edges sized to provide ahole of the selected hole diameter, relief flutes extending helically ofthe drill shank from the cutter edges a distance greater than theselected depth of the blind hole, a flat, rigid washer providing a flatfront side that serves as an abutment for automatically limiting depthof penetration of the drill shank, said washer having a central circularhole of a dimension only slightly greater than the selected diameter ofthe blind hole to provide a slip fit of the washer onto the drill shankto surround the drill shank and the relief flutes, and weld meansrigidly mounting the washer concentrically of the fluted drill shank andat a distance from the cutting, tip corresponding to the selected depthof the blind hole, whereby the circular hole of the washer cooperateswith the relief flutes surrounded by the washer to provide passagewaysthrough which the residue of drilling is caused to be discharged uponcontinuing the rotation of the drill after the flat front side of thewasher abuts the surface of the body being drilled to terminate cuttingby the drills cutting tip.

2. A clean-out drill for drilling, and cleaning out the residue ofdrilling from, blind holes of a selected diameter and depth comprising,in combination: an elongated cylindrical drill shank of a length greaterthan the selected depth of the blind hole and terminating at a cuttingtip in cutter edges sized to provide a hole of the selected holediameter, relief flutes extending helically of the drill shank from thecutter edges a distance greater than the selected depth of the blindhole, a washer with a central circular hole of a dimension slightlygreater than the selected diameter of the blind hole, and means mountingthe washer concentrically of the fluted drill shank and at a distancefrom the cutting tip corresponding to the selected depth of the blindhole, whereby the circular hole of the washer cooperates with the reliefflutes surrounded by the washer to provide passageways through which theresidue of drilling is caused to be discharged upon continuing therotation of the drill after the washer abuts to terminate cutting by thedrills cutting tip, said drill shank being initially of greater diameterthan the selected diameter of the blind hole, the

the washer being positioned to abut said shoulder means and being weldedonly at points of abutment between the washer and shoulder means so asto leave the passageways defined between the washer and relief flutesunobstructed.

1. A clean-out drill for drilling in concrete, and cleaning out the dustand residue of drilling concrete from, blind holes of a selecteddiameter and depth comprising, in combination: an elongated cylindricaldrill shank of a length greater than the selected depth of the blindhole and terminating at a cutting tip in cutter edges sized to provide ahole of the selected hole diameter, relief flutes extending helically ofthe drill shank from the cutter edges a distance greater than theselected depth of the blind hole, a flat, rigid washer providing a flatfront side that serves as an abutment for automatically limiting depthof penetration of the drill shank, said washer having a central circularhole of a dimension only slightly greater than the selected diameter ofthe blind hole to provide a slip fit of the washer onto the drill shankto surRound the drill shank and the relief flutes, and weld meansrigidly mounting the washer concentrically of the fluted drill shank andat a distance from the cutting tip corresponding to the selected depthof the blind hole, whereby the circular hole of the washer cooperateswith the relief flutes surrounded by the washer to provide passagewaysthrough which the residue of drilling is caused to be discharged uponcontinuing the rotation of the drill after the flat front side of thewasher abuts the surface of the body being drilled to terminate cuttingby the drill''s cutting tip.
 2. A clean-out drill for drilling, andcleaning out the residue of drilling from, blind holes of a selecteddiameter and depth comprising, in combination: an elongated cylindricaldrill shank of a length greater than the selected depth of the blindhole and terminating at a cutting tip in cutter edges sized to provide ahole of the selected hole diameter, relief flutes extending helically ofthe drill shank from the cutter edges a distance greater than theselected depth of the blind hole, a washer with a central circular holeof a dimension slightly greater than the selected diameter of the blindhole, and means mounting the washer concentrically of the fluted drillshank and at a distance from the cutting tip corresponding to theselected depth of the blind hole, whereby the circular hole of thewasher cooperates with the relief flutes surrounded by the washer toprovide passageways through which the residue of drilling is caused tobe discharged upon continuing the rotation of the drill after the washerabuts to terminate cutting by the drill''s cutting tip, said drill shankbeing initially of greater diameter than the selected diameter of theblind hole, the cutting tip and adjacent shank portion of the drillbeing reduced from said greater diameter to the selected diameter of theblind hole to provide shoulder means in a plane spaced from the cuttingtip of the drill, the washer''s central circular hole being of lesserdiameter than said shoulder means, and the washer being positioned toabut said shoulder means and being welded only at points of abutmentbetween the washer and shoulder means so as to leave the passagewaysdefined between the washer and relief flutes unobstructed.